2009-12-13 22:07:16 +00:00
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# Underscore.js
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# (c) 2009 Jeremy Ashkenas, DocumentCloud Inc.
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# Underscore is freely distributable under the terms of the MIT license.
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# Portions of Underscore are inspired by or borrowed from Prototype.js,
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# Oliver Steele's Functional, and John Resig's Micro-Templating.
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# For all details and documentation:
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# http://documentcloud.github.com/underscore/
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=>
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# ------------------------- Baseline setup ---------------------------------
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# Establish the root object, "window" in the browser, or "global" on the server.
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root: this
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# Save the previous value of the "_" variable.
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previousUnderscore: root._
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# If Underscore is called as a function, it returns a wrapped object that
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# can be used OO-style. This wrapper holds altered versions of all the
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# underscore functions. Wrapped objects may be chained.
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wrapper: obj => this._wrapped = obj.
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# Establish the object that gets thrown to break out of a loop iteration.
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breaker: if typeof StopIteration is 'undefined' then '__break__' else StopIteration.
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# Create a safe reference to the Underscore object for reference below.
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_: root._: obj => new wrapper(obj).
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# Export the Underscore object for CommonJS.
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exports._: _ if typeof exports aint 'undefined'
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# Create quick reference variables for speed access to core prototypes.
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slice: Array.prototype.slice
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unshift: Array.prototype.unshift
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toString: Object.prototype.toString
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hasOwnProperty: Object.prototype.hasOwnProperty
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propertyIsEnumerable: Object.prototype.propertyIsEnumerable
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# Current version.
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_.VERSION: '0.5.1'
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# ------------------------ Collection Functions: ---------------------------
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# The cornerstone, an each implementation.
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# Handles objects implementing forEach, arrays, and raw objects.
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_.each: obj, iterator, context =>
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index: 0
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try
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if obj.forEach then return obj.forEach(iterator, context).
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if _.isArray(obj) or _.isArguments(obj) then return iterator.call(context, item, i, obj) for item, i in obj..
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iterator.call(context, obj[key], key, obj) for key in _.keys(obj).
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catch e
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throw e if e aint breaker.
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obj.
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# Return the results of applying the iterator to each element. Use JavaScript
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# 1.6's version of map, if possible.
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_.map = obj, iterator, context =>
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return obj.map(iterator, context) if (obj and _.isFunction(obj.map))
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results = []
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_.each(obj, (value, index, list =>
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results.push(iterator.call(context, value, index, list))
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))
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results
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# Reduce builds up a single result from a list of values. Also known as
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# inject, or foldl. Uses JavaScript 1.8's version of reduce, if possible.
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_.reduce = obj, memo, iterator, context =>
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return obj.reduce(_.bind(iterator, context), memo) if (obj and _.isFunction(obj.reduce))
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_.each(obj, (value, index, list =>
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memo = iterator.call(context, memo, value, index, list)
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))
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memo
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# The right-associative version of reduce, also known as foldr. Uses
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# JavaScript 1.8's version of reduceRight, if available.
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_.reduceRight = function(obj, memo, iterator, context) {
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if (obj && _.isFunction(obj.reduceRight)) return obj.reduceRight(_.bind(iterator, context), memo);
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var reversed = _.clone(_.toArray(obj)).reverse();
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_.each(reversed, function(value, index) {
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memo = iterator.call(context, memo, value, index, obj);
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});
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return memo;
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};
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# Return the first value which passes a truth test.
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_.detect = function(obj, iterator, context) {
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var result;
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_.each(obj, function(value, index, list) {
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if (iterator.call(context, value, index, list)) {
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result = value;
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_.breakLoop();
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}
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});
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return result;
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};
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# Return all the elements that pass a truth test. Use JavaScript 1.6's
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# filter(), if it exists.
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_.select = function(obj, iterator, context) {
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if (obj && _.isFunction(obj.filter)) return obj.filter(iterator, context);
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var results = [];
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_.each(obj, function(value, index, list) {
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iterator.call(context, value, index, list) && results.push(value);
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});
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return results;
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};
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# Return all the elements for which a truth test fails.
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_.reject = function(obj, iterator, context) {
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var results = [];
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_.each(obj, function(value, index, list) {
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!iterator.call(context, value, index, list) && results.push(value);
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});
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return results;
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};
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# Determine whether all of the elements match a truth test. Delegate to
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# JavaScript 1.6's every(), if it is present.
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_.all = function(obj, iterator, context) {
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iterator = iterator || _.identity;
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if (obj && _.isFunction(obj.every)) return obj.every(iterator, context);
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var result = true;
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_.each(obj, function(value, index, list) {
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if (!(result = result && iterator.call(context, value, index, list))) _.breakLoop();
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});
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return result;
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};
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# Determine if at least one element in the object matches a truth test. Use
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# JavaScript 1.6's some(), if it exists.
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_.any = function(obj, iterator, context) {
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iterator = iterator || _.identity;
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if (obj && _.isFunction(obj.some)) return obj.some(iterator, context);
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var result = false;
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_.each(obj, function(value, index, list) {
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if (result = iterator.call(context, value, index, list)) _.breakLoop();
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});
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return result;
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};
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# Determine if a given value is included in the array or object,
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# based on '==='.
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_.include = function(obj, target) {
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if (_.isArray(obj)) return _.indexOf(obj, target) != -1;
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var found = false;
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_.each(obj, function(value) {
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if (found = value === target) _.breakLoop();
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});
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return found;
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};
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# Invoke a method with arguments on every item in a collection.
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_.invoke = function(obj, method) {
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var args = _.rest(arguments, 2);
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return _.map(obj, function(value) {
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return (method ? value[method] : value).apply(value, args);
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});
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};
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# Convenience version of a common use case of map: fetching a property.
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_.pluck = function(obj, key) {
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return _.map(obj, function(value){ return value[key]; });
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};
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# Return the maximum item or (item-based computation).
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_.max = function(obj, iterator, context) {
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if (!iterator && _.isArray(obj)) return Math.max.apply(Math, obj);
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var result = {computed : -Infinity};
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_.each(obj, function(value, index, list) {
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var computed = iterator ? iterator.call(context, value, index, list) : value;
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computed >= result.computed && (result = {value : value, computed : computed});
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});
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return result.value;
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};
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# Return the minimum element (or element-based computation).
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_.min = function(obj, iterator, context) {
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if (!iterator && _.isArray(obj)) return Math.min.apply(Math, obj);
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var result = {computed : Infinity};
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_.each(obj, function(value, index, list) {
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var computed = iterator ? iterator.call(context, value, index, list) : value;
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computed < result.computed && (result = {value : value, computed : computed});
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});
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return result.value;
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};
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# Sort the object's values by a criteria produced by an iterator.
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_.sortBy = function(obj, iterator, context) {
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return _.pluck(_.map(obj, function(value, index, list) {
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return {
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value : value,
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criteria : iterator.call(context, value, index, list)
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};
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}).sort(function(left, right) {
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var a = left.criteria, b = right.criteria;
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return a < b ? -1 : a > b ? 1 : 0;
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}), 'value');
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};
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# Use a comparator function to figure out at what index an object should
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# be inserted so as to maintain order. Uses binary search.
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_.sortedIndex = function(array, obj, iterator) {
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iterator = iterator || _.identity;
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var low = 0, high = array.length;
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while (low < high) {
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var mid = (low + high) >> 1;
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iterator(array[mid]) < iterator(obj) ? low = mid + 1 : high = mid;
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}
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return low;
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};
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# Convert anything iterable into a real, live array.
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_.toArray = function(iterable) {
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if (!iterable) return [];
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if (iterable.toArray) return iterable.toArray();
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if (_.isArray(iterable)) return iterable;
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if (_.isArguments(iterable)) return slice.call(iterable);
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return _.map(iterable, function(val){ return val; });
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};
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# Return the number of elements in an object.
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_.size = function(obj) {
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return _.toArray(obj).length;
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};
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/*-------------------------- Array Functions: ------------------------------*/
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# Get the first element of an array. Passing "n" will return the first N
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# values in the array. Aliased as "head". The "guard" check allows it to work
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# with _.map.
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_.first = function(array, n, guard) {
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return n && !guard ? slice.call(array, 0, n) : array[0];
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};
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# Returns everything but the first entry of the array. Aliased as "tail".
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# Especially useful on the arguments object. Passing an "index" will return
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# the rest of the values in the array from that index onward. The "guard"
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//check allows it to work with _.map.
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_.rest = function(array, index, guard) {
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return slice.call(array, _.isUndefined(index) || guard ? 1 : index);
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};
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# Get the last element of an array.
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_.last = function(array) {
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return array[array.length - 1];
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};
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# Trim out all falsy values from an array.
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_.compact = function(array) {
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return _.select(array, function(value){ return !!value; });
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};
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# Return a completely flattened version of an array.
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_.flatten = function(array) {
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return _.reduce(array, [], function(memo, value) {
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if (_.isArray(value)) return memo.concat(_.flatten(value));
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memo.push(value);
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return memo;
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});
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};
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# Return a version of the array that does not contain the specified value(s).
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_.without = function(array) {
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var values = _.rest(arguments);
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return _.select(array, function(value){ return !_.include(values, value); });
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};
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# Produce a duplicate-free version of the array. If the array has already
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# been sorted, you have the option of using a faster algorithm.
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_.uniq = function(array, isSorted) {
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return _.reduce(array, [], function(memo, el, i) {
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if (0 == i || (isSorted === true ? _.last(memo) != el : !_.include(memo, el))) memo.push(el);
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return memo;
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});
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};
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# Produce an array that contains every item shared between all the
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# passed-in arrays.
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_.intersect = function(array) {
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var rest = _.rest(arguments);
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return _.select(_.uniq(array), function(item) {
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return _.all(rest, function(other) {
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return _.indexOf(other, item) >= 0;
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});
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});
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};
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# Zip together multiple lists into a single array -- elements that share
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# an index go together.
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_.zip = function() {
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var args = _.toArray(arguments);
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var length = _.max(_.pluck(args, 'length'));
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var results = new Array(length);
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for (var i=0; i<length; i++) results[i] = _.pluck(args, String(i));
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return results;
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};
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# If the browser doesn't supply us with indexOf (I'm looking at you, MSIE),
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# we need this function. Return the position of the first occurence of an
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# item in an array, or -1 if the item is not included in the array.
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_.indexOf = function(array, item) {
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if (array.indexOf) return array.indexOf(item);
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for (var i=0, l=array.length; i<l; i++) if (array[i] === item) return i;
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return -1;
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};
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# Provide JavaScript 1.6's lastIndexOf, delegating to the native function,
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# if possible.
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_.lastIndexOf = function(array, item) {
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if (array.lastIndexOf) return array.lastIndexOf(item);
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var i = array.length;
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while (i--) if (array[i] === item) return i;
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return -1;
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};
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# Generate an integer Array containing an arithmetic progression. A port of
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# the native Python range() function. See:
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# http://docs.python.org/library/functions.html#range
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_.range = function(start, stop, step) {
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var a = _.toArray(arguments);
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var solo = a.length <= 1;
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var start = solo ? 0 : a[0], stop = solo ? a[0] : a[1], step = a[2] || 1;
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var len = Math.ceil((stop - start) / step);
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if (len <= 0) return [];
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var range = new Array(len);
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for (var i = start, idx = 0; true; i += step) {
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if ((step > 0 ? i - stop : stop - i) >= 0) return range;
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range[idx++] = i;
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}
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};
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/* ----------------------- Function Functions: -----------------------------*/
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# Create a function bound to a given object (assigning 'this', and arguments,
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# optionally). Binding with arguments is also known as 'curry'.
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_.bind = function(func, obj) {
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var args = _.rest(arguments, 2);
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return function() {
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return func.apply(obj || root, args.concat(_.toArray(arguments)));
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};
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};
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|
# Bind all of an object's methods to that object. Useful for ensuring that
|
|
|
|
# all callbacks defined on an object belong to it.
|
|
|
|
_.bindAll = function(obj) {
|
|
|
|
var funcs = _.rest(arguments);
|
|
|
|
if (funcs.length == 0) funcs = _.functions(obj);
|
|
|
|
_.each(funcs, function(f) { obj[f] = _.bind(obj[f], obj); });
|
|
|
|
return obj;
|
|
|
|
};
|
|
|
|
|
|
|
|
# Delays a function for the given number of milliseconds, and then calls
|
|
|
|
# it with the arguments supplied.
|
|
|
|
_.delay = function(func, wait) {
|
|
|
|
var args = _.rest(arguments, 2);
|
|
|
|
return setTimeout(function(){ return func.apply(func, args); }, wait);
|
|
|
|
};
|
|
|
|
|
|
|
|
# Defers a function, scheduling it to run after the current call stack has
|
|
|
|
# cleared.
|
|
|
|
_.defer = function(func) {
|
|
|
|
return _.delay.apply(_, [func, 1].concat(_.rest(arguments)));
|
|
|
|
};
|
|
|
|
|
|
|
|
# Returns the first function passed as an argument to the second,
|
|
|
|
# allowing you to adjust arguments, run code before and after, and
|
|
|
|
# conditionally execute the original function.
|
|
|
|
_.wrap = function(func, wrapper) {
|
|
|
|
return function() {
|
|
|
|
var args = [func].concat(_.toArray(arguments));
|
|
|
|
return wrapper.apply(wrapper, args);
|
|
|
|
};
|
|
|
|
};
|
|
|
|
|
|
|
|
# Returns a function that is the composition of a list of functions, each
|
|
|
|
# consuming the return value of the function that follows.
|
|
|
|
_.compose = function() {
|
|
|
|
var funcs = _.toArray(arguments);
|
|
|
|
return function() {
|
|
|
|
var args = _.toArray(arguments);
|
|
|
|
for (var i=funcs.length-1; i >= 0; i--) {
|
|
|
|
args = [funcs[i].apply(this, args)];
|
|
|
|
}
|
|
|
|
return args[0];
|
|
|
|
};
|
|
|
|
};
|
|
|
|
|
|
|
|
/* ------------------------- Object Functions: ---------------------------- */
|
|
|
|
|
|
|
|
# Retrieve the names of an object's properties.
|
|
|
|
_.keys = function(obj) {
|
|
|
|
if(_.isArray(obj)) return _.range(0, obj.length);
|
|
|
|
var keys = [];
|
|
|
|
for (var key in obj) if (hasOwnProperty.call(obj, key)) keys.push(key);
|
|
|
|
return keys;
|
|
|
|
};
|
|
|
|
|
|
|
|
# Retrieve the values of an object's properties.
|
|
|
|
_.values = function(obj) {
|
|
|
|
return _.map(obj, _.identity);
|
|
|
|
};
|
|
|
|
|
|
|
|
# Return a sorted list of the function names available in Underscore.
|
|
|
|
_.functions = function(obj) {
|
|
|
|
return _.select(_.keys(obj), function(key){ return _.isFunction(obj[key]); }).sort();
|
|
|
|
};
|
|
|
|
|
|
|
|
# Extend a given object with all of the properties in a source object.
|
|
|
|
_.extend = function(destination, source) {
|
|
|
|
for (var property in source) destination[property] = source[property];
|
|
|
|
return destination;
|
|
|
|
};
|
|
|
|
|
|
|
|
# Create a (shallow-cloned) duplicate of an object.
|
|
|
|
_.clone = function(obj) {
|
|
|
|
if (_.isArray(obj)) return obj.slice(0);
|
|
|
|
return _.extend({}, obj);
|
|
|
|
};
|
|
|
|
|
|
|
|
# Perform a deep comparison to check if two objects are equal.
|
|
|
|
_.isEqual = function(a, b) {
|
|
|
|
# Check object identity.
|
|
|
|
if (a === b) return true;
|
|
|
|
# Different types?
|
|
|
|
var atype = typeof(a), btype = typeof(b);
|
|
|
|
if (atype != btype) return false;
|
|
|
|
# Basic equality test (watch out for coercions).
|
|
|
|
if (a == b) return true;
|
|
|
|
# One is falsy and the other truthy.
|
|
|
|
if ((!a && b) || (a && !b)) return false;
|
|
|
|
# One of them implements an isEqual()?
|
|
|
|
if (a.isEqual) return a.isEqual(b);
|
|
|
|
# Check dates' integer values.
|
|
|
|
if (_.isDate(a) && _.isDate(b)) return a.getTime() === b.getTime();
|
|
|
|
# Both are NaN?
|
|
|
|
if (_.isNaN(a) && _.isNaN(b)) return true;
|
|
|
|
# Compare regular expressions.
|
|
|
|
if (_.isRegExp(a) && _.isRegExp(b))
|
|
|
|
return a.source === b.source &&
|
|
|
|
a.global === b.global &&
|
|
|
|
a.ignoreCase === b.ignoreCase &&
|
|
|
|
a.multiline === b.multiline;
|
|
|
|
# If a is not an object by this point, we can't handle it.
|
|
|
|
if (atype !== 'object') return false;
|
|
|
|
# Check for different array lengths before comparing contents.
|
|
|
|
if (a.length && (a.length !== b.length)) return false;
|
|
|
|
# Nothing else worked, deep compare the contents.
|
|
|
|
var aKeys = _.keys(a), bKeys = _.keys(b);
|
|
|
|
# Different object sizes?
|
|
|
|
if (aKeys.length != bKeys.length) return false;
|
|
|
|
# Recursive comparison of contents.
|
|
|
|
for (var key in a) if (!_.isEqual(a[key], b[key])) return false;
|
|
|
|
return true;
|
|
|
|
};
|
|
|
|
|
|
|
|
# Is a given array or object empty?
|
|
|
|
_.isEmpty = function(obj) {
|
|
|
|
return _.keys(obj).length == 0;
|
|
|
|
};
|
|
|
|
|
|
|
|
# Is a given value a DOM element?
|
|
|
|
_.isElement = function(obj) {
|
|
|
|
return !!(obj && obj.nodeType == 1);
|
|
|
|
};
|
|
|
|
|
|
|
|
# Is a given variable an arguments object?
|
|
|
|
_.isArguments = function(obj) {
|
|
|
|
return obj && _.isNumber(obj.length) && !_.isArray(obj) && !propertyIsEnumerable.call(obj, 'length');
|
|
|
|
};
|
|
|
|
|
|
|
|
# Is the given value NaN -- this one is interesting. NaN != NaN, and
|
|
|
|
# isNaN(undefined) == true, so we make sure it's a number first.
|
|
|
|
_.isNaN = function(obj) {
|
|
|
|
return _.isNumber(obj) && isNaN(obj);
|
|
|
|
};
|
|
|
|
|
|
|
|
# Is a given value equal to null?
|
|
|
|
_.isNull = function(obj) {
|
|
|
|
return obj === null;
|
|
|
|
};
|
|
|
|
|
|
|
|
# Is a given variable undefined?
|
|
|
|
_.isUndefined = function(obj) {
|
|
|
|
return typeof obj == 'undefined';
|
|
|
|
};
|
|
|
|
|
|
|
|
# Invokes interceptor with the obj, and then returns obj.
|
|
|
|
# The primary purpose of this method is to "tap into" a method chain, in order to perform operations on intermediate results within the chain.
|
|
|
|
_.tap = function(obj, interceptor) {
|
|
|
|
interceptor(obj);
|
|
|
|
return obj;
|
|
|
|
}
|
|
|
|
|
|
|
|
# Define the isArray, isDate, isFunction, isNumber, isRegExp, and isString
|
|
|
|
# functions based on their toString identifiers.
|
|
|
|
var types = ['Array', 'Date', 'Function', 'Number', 'RegExp', 'String'];
|
|
|
|
for (var i=0, l=types.length; i<l; i++) {
|
|
|
|
(function() {
|
|
|
|
var identifier = '[object ' + types[i] + ']';
|
|
|
|
_['is' + types[i]] = function(obj) { return toString.call(obj) == identifier; };
|
|
|
|
})();
|
|
|
|
}
|
|
|
|
|
|
|
|
/* -------------------------- Utility Functions: -------------------------- */
|
|
|
|
|
|
|
|
# Run Underscore.js in noConflict mode, returning the '_' variable to its
|
|
|
|
# previous owner. Returns a reference to the Underscore object.
|
|
|
|
_.noConflict = function() {
|
|
|
|
root._ = previousUnderscore;
|
|
|
|
return this;
|
|
|
|
};
|
|
|
|
|
|
|
|
# Keep the identity function around for default iterators.
|
|
|
|
_.identity = function(value) {
|
|
|
|
return value;
|
|
|
|
};
|
|
|
|
|
|
|
|
# Break out of the middle of an iteration.
|
|
|
|
_.breakLoop = function() {
|
|
|
|
throw breaker;
|
|
|
|
};
|
|
|
|
|
|
|
|
# Generate a unique integer id (unique within the entire client session).
|
|
|
|
# Useful for temporary DOM ids.
|
|
|
|
var idCounter = 0;
|
|
|
|
_.uniqueId = function(prefix) {
|
|
|
|
var id = idCounter++;
|
|
|
|
return prefix ? prefix + id : id;
|
|
|
|
};
|
|
|
|
|
|
|
|
# JavaScript templating a-la ERB, pilfered from John Resig's
|
|
|
|
# "Secrets of the JavaScript Ninja", page 83.
|
|
|
|
_.template = function(str, data) {
|
|
|
|
var fn = new Function('obj',
|
|
|
|
'var p=[],print=function(){p.push.apply(p,arguments);};' +
|
|
|
|
'with(obj){p.push(\'' +
|
|
|
|
str
|
|
|
|
.replace(/[\r\t\n]/g, " ")
|
|
|
|
.split("<%").join("\t")
|
|
|
|
.replace(/((^|%>)[^\t]*)'/g, "$1\r")
|
|
|
|
.replace(/\t=(.*?)%>/g, "',$1,'")
|
|
|
|
.split("\t").join("');")
|
|
|
|
.split("%>").join("p.push('")
|
|
|
|
.split("\r").join("\\'")
|
|
|
|
+ "');}return p.join('');");
|
|
|
|
return data ? fn(data) : fn;
|
|
|
|
};
|
|
|
|
|
|
|
|
/*------------------------------- Aliases ----------------------------------*/
|
|
|
|
|
|
|
|
_.forEach = _.each;
|
|
|
|
_.foldl = _.inject = _.reduce;
|
|
|
|
_.foldr = _.reduceRight;
|
|
|
|
_.filter = _.select;
|
|
|
|
_.every = _.all;
|
|
|
|
_.some = _.any;
|
|
|
|
_.head = _.first;
|
|
|
|
_.tail = _.rest;
|
|
|
|
_.methods = _.functions;
|
|
|
|
|
|
|
|
/*------------------------ Setup the OOP Wrapper: --------------------------*/
|
|
|
|
|
|
|
|
# Helper function to continue chaining intermediate results.
|
|
|
|
var result = function(obj, chain) {
|
|
|
|
return chain ? _(obj).chain() : obj;
|
|
|
|
};
|
|
|
|
|
|
|
|
# Add all of the Underscore functions to the wrapper object.
|
|
|
|
_.each(_.functions(_), function(name) {
|
|
|
|
var method = _[name];
|
|
|
|
wrapper.prototype[name] = function() {
|
|
|
|
unshift.call(arguments, this._wrapped);
|
|
|
|
return result(method.apply(_, arguments), this._chain);
|
|
|
|
};
|
|
|
|
});
|
|
|
|
|
|
|
|
# Add all mutator Array functions to the wrapper.
|
|
|
|
_.each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) {
|
|
|
|
var method = Array.prototype[name];
|
|
|
|
wrapper.prototype[name] = function() {
|
|
|
|
method.apply(this._wrapped, arguments);
|
|
|
|
return result(this._wrapped, this._chain);
|
|
|
|
};
|
|
|
|
});
|
|
|
|
|
|
|
|
# Add all accessor Array functions to the wrapper.
|
|
|
|
_.each(['concat', 'join', 'slice'], function(name) {
|
|
|
|
var method = Array.prototype[name];
|
|
|
|
wrapper.prototype[name] = function() {
|
|
|
|
return result(method.apply(this._wrapped, arguments), this._chain);
|
|
|
|
};
|
|
|
|
});
|
|
|
|
|
|
|
|
# Start chaining a wrapped Underscore object.
|
|
|
|
wrapper.prototype.chain = function() {
|
|
|
|
this._chain = true;
|
|
|
|
return this;
|
|
|
|
};
|
|
|
|
|
|
|
|
# Extracts the result from a wrapped and chained object.
|
|
|
|
wrapper.prototype.value = function() {
|
|
|
|
return this._wrapped;
|
|
|
|
};
|
|
|
|
|
|
|
|
()
|